Pavement repair

ABSTRACT

An improvement in pavement repair consists of a ready-to-use molded special asphalt composition plug which is intended for filling small holes in pavements. The invention also embraces an improved package in which numerous asphalt plugs are contained in a gang type disposable plastic matrix which serves the triple function of manufacturing mold and multiple container for shipping and storing the plugs until they are desired for use in repairing pavement holes. The special composition plug is at least 50 percent by weight of A.S.T.M. asphalt D-312, Types I, II, III and IV containing about 2 to 4 percent by weight of rubber. An optional third ingredient is up to 30 percent by weight of finely divided limestone or portland cement.

Q 1 United States Patent [1 1 3,699,854 Doherty Oct. 24, 1972 [s41 PAVEMENT REPAIR 2,955,044 10/1960 Tupper ..99/171 [72] Inventor: Walter Dohefly, Carmel, 2,889,922 6/1959 Clarvoe ..206/56 Primary Examiner-Jacob L. Nackenoff Filed; March 1971 Attorney-Edward H. Valance [21] Appl. No.: 120,675 [57] ABSTRACT Related Application Data An improvement in pavement repair consists of a [63] Continuatiomimpan f Sen No 04 02 ready-to-use molded special asphalt composition plug March 6, 1969 abandone which is intended for filling small holes in pavements. The invention also embraces an improved package in 52] us. Cl ..94/22, 52/302 which numerous asphalt Plugs are Contained in a gang [51 Int. Cl. ..E01c 21/00 type diSPOSabIe Plastic mam'x which Serves the triple of Search 2 function Of manufacturing mold and multiple con- 2O6/56. 94723 52/309 tainer for shipping and storing the plugs until they are desired for use in repairin vement holes. The spe- 56 cial composition plug is at t 50 percent by weight I 1 References c'ted of A.S.T.M. asphalt 13-312," pes I, II, III and IV con- UNITED STATES PATENTS taining about 2 to 4 percent by weight of rubber. An optional third ingredient is up to 30 percent by weight ,390,498 7/1968 Roy ..52/302 f l 1 2,612,261 9/1952 Percopo ..206/63.2 fine y dm ed hmestone or and cement 2,182,454 l2/ 1939 Sherman ..62/ 103.5 5 Claims, 3 Drawing Figures PAVEMENT REPAIR This application is a continuation-in-part of U.S. ap-

plication Ser. No. 804,802, filed Mar. 6, 1969 now abandoned.

This invention relates to improvements in the repair of pavements and more particularly pertains to the repair of small holes in pavements by the filling of such holes with bituminous material of predetermined and preformed convenient shapes which material is packaged in a plastic gang type mold with truncated conical cavities. From this mold such preformed bituminous shapes are easily and conveniently removed or stored until needed for use.

BACKGROUND AND PRIOR ART The art of paving and repairing building materials is. old and well-developed. However, improved materials and methods of packaging and using such repair materials are continually under'development. In the building industry, for example, a recent development involves preformed plugs made of yieldable plastic or synthetic resin for filling holes left during construction of walls and foundations as disclosed in US. Pat. No. 3,390,498 to Roy. Furthermore, US. Pat. No. 2,889,922 to Clairvoe discribes a convenient method of packaging adhesives such as certain asphalt compositions in pouches which are easily rupturable for on-site use in building and repairing. Nevertheless, despite a long felt need for a simple, inexpensive and convenient method of repairing pavements with small holes therein, there has been no teaching of the present invention which employs a special composition of asphalt and minor portion of rubber with certain optional materials.

Conventional blacktop pavements are often subject to wear and tear and weathering in the region of small holes which become enlarged pot-holes and do extensive damage to the vehicles using such pavements. Very often these large and dangerous pot-holes are caused by the enlargement of so-called large bar-holes. Such bar-holes are made in pavements of asphalt or blacktop as well as other types of pavements such as concrete or gravel. The bar-holes are the result of drilling in the pavement by workers who may be surveying an area for the exact location of pipes or other objects located beneath the surface of the pavement. For example, it may be necessary to ascertain the exact location of a gas leak by this method. This is a common practice, particularly in metropolitan areas where there is a heavy flow of traffic over streets where such holes in the pavements have been made. In a short time the combination of heavy traffic and weathering produces dangerous pot-holes and does extensive damage to the pavement. Since many of these bar holes are necessary throughout the streets of such metropolitan areas there has been a need for a convenient, rapid and easy method of repairing such holes before they become enlarged and dangerous. The present invention is intended to solve the problem by providing an easy, convenient and rapid method of filling these bar-holes or other small holes in pavements, particularly wherethere is a need to protect the pavements against damage due to heavy traffic and weathering.

It is an object of the present invention to provide a method of filling small holes in pavement easily and quickly by plugging such holes with a bituminous material in a pre-formed shape.

It is a further object of the invention to provide an improved means of preforming shapes of bituminous material for use in filling small holes in pavements.

It is a further object of the invention to provide a combined packaging and forming matrix for the preparation of preformed shapes of bituminous material for use in the repairing of small holes in pavements.

Another object of this invention is to provide a special asphalt composition in pre-formed plug shapes which comprise from about 2 to about 4 percent by weight of rubber and optionally from 0 up to about 30 percent by weight of finely divided limestone or portland cement, the main element in this composition being asphalt whose softening point ranges from about F to about 225 F and corresponds to A.S.T.M. D-3 l 2 specification, (Types I, II, III and IV).

In connection with the following more detailed description ofv this invention, reference is made to the accompanying drawings showing the preformed shapes of bituminous material or asphalt and the combination mold and container for such shapes.

FIG. 1 is a perspective view of the mold in having bituminous material poured into the cavities.

FIG. 2 is a perspective view of two typical conical shapes of asphalt after removal from the combination mold and container.

FIG. 3 is a schematic view of the conical shape in the process of filling a bar-hole according to the invention.

Referring now to the drawings, FIG. 1 illustrates a combination mold and container 10 with bituminous material therein 13. The walls of the round mold cavity 12 are tapered with the circular mouth being of greater diameter than that of the circumference of the bottom of the mold 11 cavity. A lip is often convenient and may run around the outer periphery of the top portion of the mold.

As shown in FIG. 1, a bituminous material, namely a durable processed A.S.T.M. D-3 l 2 asphalt 13 is placed in the conical recesses of a multiple gang type mold 10. FIG. 2 shows various shapes A, B of such hardened asphalt which have been preformed and removed from the mold matrix as illustrated l4, 15 in FIG. 2. FIG. 3 displays a preformed plug of said asphalt 18 in the process of being manually plugged into a small barhole 17 in a pavement l6 by the use of a hammer 20 and wooden board 19 to force this plug of asphalt into the hole.

Actually this invention pertains to the filling of small holes of any size in pavements, although in practice such holes may range from a small fraction of an inch to several inches in diameter. Such holes may range from about Y4 inch to about 2 /4 inch in diameter and result from the drilling of holes in pavements of asphalt, concrete, macadam or gravel. It has been found that a plug of said asphalt should be selected which is of somewhat larger diameter at the base of the truncated cone and of somewhat smaller diameter at the top of such truncated cone than the hole to be filled in the pavement. This permits insertion of the smaller top of the asphalt cone into the hole and complete filling of the hole upon movement of the shape downward so that the larger diameter base of the truncated conical shape completely fits into the hole and is pressed flat to make a smooth repaired pavement without substantial bump after the process is completed.

The bituminous material which is conveniently used is an asphalt composition which has for many years been useful in the preparation of built up roof coverings such as A.S.T.M. D-312 Asphalt, Types 1, II,

III and IV, and combinations thereof. The asphalt com- 5 position which is preferred for use in temperate climates such as in cities of North America like New York, Miami, Chicago, St. Louis and San Francisco, is A.S.T.M. D-3l2, type IV. For colder climates, e.g., Duluth, Montreal and Quebec softer types of A.S.T.M. D-3 12 may be preferred, such as for example, Type Ill. Under certain circumstances in colder climates, e.g., in portions of Canada and Alaska, A.S.T.M. D-3 12, Types I and II may be used. In general, an asphalt of the D-3l2 type is used wherein softening in summer when warmer is not too great to make the repair material flow excessively and open up the repaired hole. As described above, a preferred type of D-3 l 2 asphalt for use in continental U.S. is Type IV. The following Table 1 indicates the characteristics of the asphalts according to the invention:

TABLE I Characteristics f A.S.T.M. D-312 Asphalts Type Type 1 Type 11 Ill Type IV min. max. min. max. min. max. min. max.

135 lSO I60 175 180 200 205 Softening Point (Ring and Ball Method) Penetration: 3

F (0C) 200g,'60 sec. 77 F (25C) 100g, 5 sec. 115 F (46C) The asphalts described in Table I also have the following characteristics as set out in Table II below:

TABLE II Properties Of A.S.T.M. D-312 Asphalts Types I-IV Type: I ii III IV Flash Point (Cleveland open cup) 437 437 437 437 Ductility at 77 F (25C) (5cm per min), cm [0 3 3 [.5

mineral-stabilized or native asphalt) In preparing the biutminous material for the plugs according to the invention generally the asphalt described above is heated until it becomes molten and is then poured into a suitable mold and receptacle as described herein. The bituminous material advantageously contains rubber in minor amounts, as well as other fillers such as limestone and portland cement. A convenient source'of rubber for use in the preparation of the bituminous material is reclaimed rubber from scraping of automobile and truck tires for recapping. These rubber scraps are conveniently used in finely divided sizes as measured by mesh sieve sizes. For example, the rubber may be used in finely divided state in mesh sizes from about No. 4 to No. 50 mesh, preferably from 16 to 30 mesh sieve size (American Standard screen sizes). As has been indicated the rubber is used in amount less than 50 percent by weight based on the total amount of asphalt used; Generally, a small amount of rubber is used. In a preferred embodiment, from-about 2 to about 4 percent of rubber by weight of 16 to 30 mesh screen size particles is used.

Sometimes, particularly when the plug repair material is expected to be used in warmer climates or seasons, a filler such as finely divided limestone may also be used in minor amounts, from about 20 to about 30 percent by weight preferably, although smaller amounts can be used under certain circumstances.

The proportions of (a) filler (limestone or portland cement), and (b) rubber are so adjusted at all times that the asphalt is not less than at least 50 percent by weight of the totalcomposition used for making the repair plug. Normally, the plug contains not less than about 65 percent by weight of A.S.T.M. D-3 l 2 asphalt. Where only asphalt and rubber are used to make the repair plugs in a preferred embodiment the proportion by weight of asphalt ranges from about 96 to about 98 percent by weight.

Before pouring the aforesaid asphalt composition into the molds, a release molding compound can be advantageously sprayed inside the molds, such as for example, Dow Corning 200 Silicone Fluid of 350 centistokes viscosity, in order to permit forming of the asphalt composition in the mold cavities and make it easy to release the shapes when desired. During pouring into the mold, the asphalt is cooled for example in a tank of cool running water. When the asphalt in the molds has cooled and solidified, the molds containing the asphalt plugs can be stored until needed for use. Another example of a suitable mold release compound is Humble Oil Companys Corexit No. 7669.

It has been found that the mold is conveniently made of a disposable plastic material such as high impact polystyrene which may vary from 3 to 35 thousandths of an inch in thickness. However, any relatively thin flexible plastic material can be used for the multiple gang type mold and container. Besides polystyrene materials, other plastic materials such as polyvinylchloride, polyethylene, polypropylene, polybutylene, and acrylonitrile-butadienestyrene copolymeric materials can also be employed. It is possible, too, that other materials such as thin metal may be used, although plastic is preferred for the mold because it is cheap, flexible, and promotes easy removal of the plugs. The metal may be aluminum or tin, for example.

EXAMPLE I TABLE III Size Of Asphalt Composition Plug Repair Materials Bottom Top Diameter Diameter Size of hole to be of of Length of Repair Repaired Repair plug repair plug repair plug Plug (Inches) (Inches) (Inches) (Inches) A l /5 1 V4 2 C I 36 l h 2 3 E 2 V4 2 2 A 3 The gang-type mold-receptacles are maintained cool in a tank of cold water during pouring of the hot asphalt composition and then are retained in the tank until the composition cools to room temperature and hardens. Before filling, these gang-type mold-receptacles of high impact polystyrene thickness approximately 0.003 inch are first sprayed interiorly with a silicone release compound, Humble Oil Companys Corexit No. 7669. When a plug is desired for repair of a hole in a pavement the release compound facilitates removal of the asphalt from the mold-receptacle of polystyrene.

If, in the preceding Example, in place of the release compound Corexit No. 7669, another silicone compound such as Dow Coming 200 Silicone Fluid (viscosity 350 centistokes) is used, equally good results are obtained.

As is seen from Table III, in selecting the size plug for pavement repair, a plug is used which goes about of the way into the hole to be repaired. (See FIG. 6 of drawings). Thus, for a hole of l inch diameter, the repair plug C of Table III is used, and so forth. After the repair plug has been forced into the hole by hammering the excess asphalt is broken off by pounding and smoothed away.

EXAMPLE II Several different sizes of repair plugs Table III, A, B, C, D, E) are prepared as described in Example I except that in addition to the 3 parts of rubber, there is also added 25 parts of limestone dust (325 mesh, American Standard screen size), while the parts of asphalt Type IV A.S.T.M. D-3l2 's ad'ust dt 72 ts b ht. time 11? y A composition is prepared as in Example II, as follows:

20 parts limestone 4 parts rubber 76 parts asphalt EXAMPLE IV A composition is prepared as in Example II, as follows:

30 parts limestone 2 parts rubber 68 parts asphalt If in the foregoing examples portland cement is used in place of limestone dust equally good results are obtained. I I

If in the foregoing examples asphalt A.S.T.M. D-3 12 Types I, II and III are used in place of Type IV, useful repair plugs are obtained for cold weather and cold climates.

What is claimed is:

1. In the art of repairing relatively small holes in pavements bearing vehicular and pedestrian traffic, the improvement which comprises the steps of (a) preforrning at least a single plug comprising bituminous asphalt material of A.S.T.M. designation D-3 l 2 of predetermined shape in a flexible matrix having at least one mold therein adapted to store said plug until ready for use, (b) separating said plug from said mold when needed, (c) placing said plug in a relatively small hole in said pavement which hole is of smaller dimension than a portion of said preformed plug and (d) affixing said plug into said hole by applying pressure to the plug until the plug forms a relatively smooth surface integral with the surface of the pavement adjacent said hole.

2. The improved art of repairing pavement as claimed in claim 1 wherein said plug is molded of a bituminous material comprising from about 65 to about 98 percent by weight of A.S.T.M. D-3 l 2 asphalt.

3. The improved art of repairing pavement as claimed in claim 2 wherein said plug is molded of bituminous material comprising a major portion of asphalt and a minor portion of rubber.

4. The improved art of pavement repair as claimed in claim 3 wherein said plug is molded of bituminous material comprising (a) from about 96 to about 98 per cent by weight of asphalt, and (b) from about 2 to about 4 percent by weight of rubber.

5. The improved art as described in claim 2 wherein said bituminous material is composed of (a) from about 65 to about 98 percent by weight of asphalt, (b) from about 2 to about 4 percent by weight of rubber, and (c) from O to about 30 percent by weight of a filler selected from limestone dust and portland cement dust. 

1. In the art of repairing relatively small holes in pavements bearing vehicular and pedestrian traffic, the improvement which comprises the steps of (a) preforming at least a single plug comprising bituminous asphalt material of A.S.T.M. designation D312 of predetermined shape in a flexible matrix having at least one mold therein adapted to store said plug until ready for use, (b) separating said plug from said mold when needed, (c) placing said plug in a relatively small hole in said pavement which hole is of smaller dimension than a portion of said preformed plug and (d) affixing said plug into said hole by applying pressure to the plug until the plug forms a relatively smooth surface integral with the surface of the pavement adjacent said hoLe.
 2. The improved art of repairing pavement as claimed in claim 1 wherein said plug is molded of a bituminous material comprising from about 65 to about 98 percent by weight of A.S.T.M. D-312 asphalt.
 3. The improved art of repairing pavement as claimed in claim 2 wherein said plug is molded of bituminous material comprising a major portion of asphalt and a minor portion of rubber.
 4. The improved art of pavement repair as claimed in claim 3 wherein said plug is molded of bituminous material comprising (a) from about 96 to about 98 percent by weight of asphalt, and (b) from about 2 to about 4 percent by weight of rubber.
 5. The improved art as described in claim 2 wherein said bituminous material is composed of (a) from about 65 to about 98 percent by weight of asphalt, (b) from about 2 to about 4 percent by weight of rubber, and (c) from 0 to about 30 percent by weight of a filler selected from limestone dust and portland cement dust. 